Grunt vs Gulp - Beyond the Numbers

And so the evolution of front-end development continues with Gulp,
the new build system that has already garnered praise amongst many
web developers.

After spending some time reading the docs and playing around with
Gulp, I’ve finally decided to test its adoption in an existing
project that currently uses Grunt. From what I’ve seen so far,
Gulp is blazingly fast when compared to Grunt for similar tasks.

Let’s dig a bit deeper though, and get a little understanding of the
differences between Grunt and Gulp, beyond superficial speed comparisons.

In this post we’ll cover:

A shallow dive into Gulp, and how it compares with Grunt.

Things to consider when choosing between the two tools.

First Impression

One of the pain points I’ve experienced with Grunt is the over-configuration
of simple tasks. Take stylesheet compilation for example. My source files are
written in SCSS, which needs to be compiled into CSS files, then I want to run
the files through an autoprefixer for vendor prefixes. And I want this to run
each time my source files change.

As you can see, in Gulp we do not need the intermediary .tmp folder to
store the compiled, unprefixed CSS files. This means a little bit less configuration,
and saves on I/O.

Now for some time comparisons. Gulp reported that it was able to process file changes
in 2.13ms on my machine, versus the 1.298s it took Grunt.

Timing numbers reported by Grunt

Timing numbers reported by Gulp

The timing reported by both tools are not comparable though because they use different mechanisms.
If I use time on both tasks (SASS compile + autoprefixer), then the numbers are much closer:
0.641ms for Gulp and 1.235 for Grunt. Of course, this includes boot times for both tools as
well so it isn’t a perfect comparison either!

Streams all the way down

To understand Gulp you need to understand Node Streams. All Gulp plugins are
just through streams that read in data and output data. Everything can be processed
in memory, with the output of one stream piped as input to another. Much like Unix pipes.

This gives Gulp a huge speed advantage over Grunt, because I/O is very expensive when
compared to in-memory operations. On top of that, Grunt has to compile all the files even if
only one has changed, which adds additional build time.

In Grunt, we must write intermediary files to disk

In Gulp, we pipe the intermediary files in-memory to other streams

This also means that Gulp plugins are really just map-streams. Compare this with Grunt, which has
plugins of all sorts, such as running a livereload server. In Gulp, you will need to do some Node
programming to do the same thing.

Okay, but which is better?

Unfortunately, I can’t tell you which tool is better because that is a matter of preference.

I expect the speed gap between Grunt and Gulp to be much closer once Grunt 0.5 lands. The roadmap
for Grunt 0.5 includes adding support for
piping data between multiple tasks, and emitting task output as data events. This can speed up tasks
quite significantly, and might mean that configuration can be more succinct without the need of temporary
files.

One advantage that Grunt currently has over Gulp is a much wider community support, with a lot
more plugins available for it. This, of course, can change in the future as more developers adopt Gulp,
but remember that Gulp plugins are very different from Grunt plugins so don’t expect the exact same ones
to be ported over to Gulp.

The most important question to ask yourself is which philosophy do you subscribe to more? Do you
like a build system that prefers code over configuration? If so, then you may feel right at home
with Gulp. Otherwise, stick with Grunt.

Further Reading & Information

Edit #1 on 2014/01/28: I added timing numbers for comparison, although it’s not my real
focus of this post.

Edit #2 on 2014/01/30: A reader pointed out that grunt-sass would be a better comparison than grunt-contrib-compass,
because the former uses node-sass, which is what gulp-sass uses. I’ve updated the timing numbers to reflect this change.